Squamous Cell Carcinoma Staging
Staging is the process of determining whether cancer has spread and, if so, how far. The stage of the disease may affect the treatment plan.
Understanding your stage of squamous cell carcinoma
The stage is based on the size of the tumor, how deeply into the skin it has grown, and whether cancer has spread beyond the tumor to the lymph nodes. Your doctor will look at the results of the biopsy to determine the stage. If you have squamous cell carcinoma, your doctor may also recommend imaging such as CT or PET-CT scan, or testing lymph nodes near the tumor to see if the cancer has spread beyond the skin.
- Stage 0. Cancer is found only in the original tumor in the skin. It is only in the epidermis and has not spread to the dermis. Stage 0 is also called carcinoma in situ.
- Stage 1. The tumor is 2 centimeters wide or smaller. It may have spread into the dermis. Cancer does not invade the muscle, cartilage, or bone and has not spread to lymph nodes or other organs. The tumor needs to have no more than two high-risk features.
- Stage 2. The tumor is larger than 2 centimeters and may have spread from the epidermis into the dermis. Cancer does not invade the muscle, cartilage, or bone and has not spread outside the skin. It may also have high risk features such as perineural invasion. Stage 2 tumors can also be any size with two or more high-risk features.
- Stage 3. The cancer has spread to areas below the skin, such as into muscle, bone, cartilage, or lymph nodes, but only those near the original tumor. It has not spread to distant organs.
- Stage 4. The cancer can be any size and may have spread to nearby lymph nodes. It has also spread to areas outside the skin, such as to distant organs like the brain or lungs, or has invaded the skeleton (axial or appendicular) or perineural invasion of skull base.
Most non-melanoma skin cancers are Stage 0 or Stage 1. Stage 3 and 4 are relatively rare. Based on the type of cancer, the stage of cancer, your overall health, and other factors, your doctor works with you to develop a treatment plan.
High risk features for primary tumor staging
- Depth/invasion: >2 mm thickness (Breslow thickness), Clark level ≥IV, Perineural invasion
- Anatomic: Primary site ear
- Location: Primary site hair-bearing lip
- Differentiation: Poorly differentiated or undifferentiated